@media only screen and (max-width:320px) {
    html {
        font-size: 9px;
    }
}
@media only screen and (min-width:320px) and (max-width:352px) {
    html {
        font-size: 10px;
    }
}
@media only screen and (min-width:352px) and (max-width:384px) {
    html {
        font-size: 11px;
    }
}
@media only screen and (min-width:384px) and (max-width:416px) {
    html {
        font-size: 12px;
    }
}
@media only screen and (min-width:416px) and (max-width:448px) {
    html {
        font-size: 13px;
    }
}
@media only screen and (min-width:448px) and (max-width:480px) {
    html {
        font-size: 14px;
    }
}
@media only screen and (min-width:480px) and (max-width:512px) {
    html {
        font-size: 15px;
    }
}
@media only screen and (min-width:512px) and (max-width:544px) {
    html {
        font-size: 16px;
    }
}
@media only screen and (min-width:544px) and (max-width:576px) {
    html {
        font-size: 17px;
    }
}
@media only screen and (min-width:576px) and (max-width:608px) {
    html {
        font-size: 18px;
    }
}
@media only screen and (min-width:608px) and (max-width:640px) {
    html {
        font-size: 19px;
    }
}
@media only screen and (min-width:640px) {
    html {
        font-size: 20px;
    }
}